The invention relates to an apparatus for warming and moistening a respiration gas for a patient, comprising, in a housing disposed in a gas line leading to the patient and to a respiration gas vessel, a moisture reservoir consisting of gas-permeable, hygroscopic material.
There is an apparatus of this type known in which the moisture reservoir or store consists of a roller paper strip, the longitudinal axis of the roll being arranged in the direction of flow of the respiration gas. The moisture and warmth of the gas exhaled by the patient is stored in the air gaps between the paper layers of the roll. Furthermore, the paper absorbs part of the moisture and also stores part of the warmth. As the patient inhales, the inhalation gas is warmed and moistened as it passes the roll. This apparatus is unable to store enough warmth and moisture from the exhalation gas to warm and moisten adequately very dry respiration gas, e.g. in respirator treatments.
Further known in an apparatus for warming and moistening a dry respiration gas supplied to a patient which has a vessel filled with warm water, in which the inhalation gas is conveyed through the water. The gas is thereby warmed and receives a high degree of atmospheric moisture. Because of its construction, this apparatus must be disposed at a comparatively great distance from the patient such that the respiration gas in the connection line to the patient can cool down again. Furthermore, condensation water may form there. To avoid this, the connection line can be warmed in dependence on the temperature of the respiration gas measured at the patient's mouth. This produces a bulky, expensive and structurally complicated design.
From Swedish patent application No. 76 033 968 an apparatus is further known for warming and moistening a dry respiration gas supplied to a patient, which has a housing and in the housing several discs at right angles to the direction of flow of the respiration gas, of which, in each case, one is moisture-absorbing as well as heatinsulating and the adjacent one is heat-conducting. In this apparatus, because of their small surface, the heat conducting discs cannot store heat to a sufficient degree.